Spark-plug.



A11. CHAMPION.'

SPARK PLUG.

APPLICATION FILED JULY 13. |917.

1,298,888@ Patented Apr.. l, L919.

@Hoz nuls UNITED STATES PATENT oEEIoE.

ALBERT J'. CHAMIION, OF FLIN'I', MICHIGAN, ASSIGNOR TO CHAMPION IGNITION COMPANY, OF FLINT, MICHIGAN, A CORPORATION 0F MICHIGAN.

SPARK-P LUG.

Specication of Letters Patent.

l Patented Apr. 1, 1919.

Application mea Ju1y-1a, 1317. serial No. 1s2g has for its object'the morerapid dissipation of heat from the insulator. In the present state of the art it is usual to retain the insulator within the metallic housing by .clamp- 'ing' the same between opposed bearings.

Withv certain constructions this clamping is e'ected by means of a threaded bushing engaging the main casing, while with other construction a ange on the main casing 1s y turned in .to bear on the insulator. .With each construction the insulator contacts with the case at two points, first, the seat at the Ainner endwhich forms the gas-tight seal;

and second, an outer bearing where the clamping pressure is applied. Consequently the heat of the insulator can be transmitted by conduction only'through one or the other of these two bearings. The outer casing of theplug is cooled chiey. through contact with the engine vcasing and any heat transgmitted therethrough from the insulator must I .be dissipated in this way. This mnner of dissipation is too slowv for the proper cool# ing of the insulator where plugs are used with high-speed engines, and many of thel .diiiiculties that are encountered are Vdue to A too higha degree of heat in the insulator.

With my present invention Il `have greatly vincreased the rate of'heat dissipation,`first,

byutilizing a member in direct contact with the insulator for receiving the heat by conduction; andsecond, by lf'ljssipating the heat from this 'member th`ough properly-arranged radiating surface. Various specific construction maybe devised embodying the same principle, but in the drawings I have illustrated two specific forms, in which- Figure 1 is a sectional elevation of one i form ofA plugyand Fig. 2 is a similar view of a modified con-l struction. l

A is the insulator of the spat'lr-plug'and4 B is the outer casing therefor. Wit the construction shown in Fig. 1, .the insulator has a shoulder C which seated upon the bearlng D in the casing, a suitable gasket E beinginterposed therebetween to form agastight seal.A Fis an opposed shoulder on the v insulator to which the clamping pressure is applled'by turning inward a flange G on the casing, this operation loeingA preferably performed while themetal is hot.

To facilitate the dissipation of heat the member for clamping the insulator is extended outward and is provided with radiating surface.- As shown in Fig. 1, I-I is the contacting member which is interposed between the shoulder F andthe flange G and is also provided with an outwardly-extendv ing portion H', which is threaded to receive a' member I having radiating fins I. Thus the' heat which passes directly by conduction from the insulator into the member H v will be conducted outward through'the extension H and into the member I where the extended radiating surface I rapid dissipation.

will cause -With the `constructlon shown in Fig. 2,

in place of the iiange Ga threaded bushing. -J isengaged with the casing B to provide the clamping pressure onl the insulator. This bushing is'provided` with an outwardlyextending portion K having radiating fins L thereon, and'consequently the heat which is directly conducted from the insulator to' the bushing will flow outward into the ins L and will-,be dissipated.. If desired, the body ofthe casing B may be also provided with radiating insM, aS shown, so as to assist inthe heat disssipation. If'desired, a gasket. such as shown in Fig. 2, can be applied to the construction shown inFig. 1. v

What I claim as my invention isz' In a 'spark plug', the combination with a casing and an insulator seated therein. provided with an inclined shoulder and with an outwardlyextending portion, of means for applying aclamping pressure tosaidl inclined shoulder, including a member 1n heat conducting contact therewith, having an outward extension, said `member being spaced from said outwardly-extending portion of the insulator, and radiating fins on said outward extension.l

In testimony whereof I aiiix my signature.

AALBERT J. CHAMPION. 

